Underwater Channel Sounder (UCS) for Characterizing Radio Propagation in Seawater

This paper shows a system configuration of underwater channel sounder (UCS), which enables us to characterize radio propagation in seawater through multi-antenna measurement with a vector network analyzer (VNA) even in the depth of up to 500 m. The UCS has capability of constructing multi-input/multi-output (MIMO) measurement in seawater by utilizing multiple receive antennas and a single transmit antenna that moves along with a 1D stage. Multiple sensors that include a CTD sensor, a tilt meter, and a video camera are also mounted on UCS to give a record on conditions of measurement site precisely. A test dive demonstrated that the UCS works as designed in seawater with depth of around 30 m.